Fire suppression and ecosystem carbon storage
TL;DR: A 35-year controlled burning experiment in Minnesota oak savanna showed that fire frequency had a great impact on ecosystem carbon (C) stores, with most carbon stored in woody biomass.
Abstract: A 35-year controlled burning experiment in Minnesota oak savanna showed that fire frequency had a great impact on ecosystem carbon (C) stores. Specifically, compared to the historical fire regime, fire suppression led to an average of 1.8 Mg·ha−1·yr−1 of C storage, with most carbon stored in woody biomass. Forest floor carbon stores were also significantly impacted by fire frequency, but there were no detectable effects of fire suppression on carbon in soil and fine roots combined, or in woody debris. Total ecosystem C stores averaged ∼110 Mg/ha in stands experiencing presettlement fire frequencies, but ∼220 Mg/ha in stands experiencing fire suppression. If comparable rates of C storage were to occur in other ecosystems in response to the current extent of fire suppression in the United States, fire suppression in the USA might account for 8–20% of missing global carbon.
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DOI•
01 Dec 2002TL;DR: In this article, the authors consider that the sumideros de carbono are a panacea for mitigar the efectos de cambio climatico, however, distintos estudios directos or indirect, demuestran las incertidumbres of this aparent solution.
Abstract: Se considera que los sumideros de carbono son una solucion para mitigar los efectos de cambio climatico. Sin embargo, distintos estudios directos o indirectos, demuestran las incertidumbres de esta aparente solucion. Existen argumentos en contra de la propuesta de los sumideros que se pueden clasificar en cinco tipos: 1) factores ambientales que afectan a los sumideros, 2) posible ineficacia de los sumideros, 3) limitaciones temporales, 4) efectos perjudiciales de acciones tales como la inyeccion de CO2 en los oceanos y la plantacion masiva de bosques y 5) desconocimiento de los mecanismos responsables del funcionamiento de los sumideros. Estas consideraciones permiten concluir que los sumideros no son una panacea y que existen medidas por tomar que no han entrado en vigor debido a intereses particulares, principalmente la reduccion de las emisiones.
4 citations
Dissertation•
01 Aug 2015
TL;DR: Tilman et al. as discussed by the authors presented a paper on ecology, evolution and behavior in the field of ecology, biology, and ecology, with an emphasis on ecology and evolution.
Abstract: University of Minnesota Ph.D. dissertation. August 2015 . Major: Ecology, Evolution and Behavior. Advisor: David Tilman. 1 computer file (PDF); ix, 170 pages.
4 citations
Dissertation•
01 Dec 2014
4 citations
01 Jan 2014
TL;DR: In this article, the authors examined changes in woody biomass carbon stocks over a 10-year period in 136 savanna monitoring plots and statistically assessed these changes in relation to fire frequency and severity, concluding that changes to fire management have the potential to either increase or decrease rates of woody thickening relative to any underlying trend.
Abstract: Aim Many tropical savannas are undergoing a trend of increasing woody biomass, or ‘woody thickening’. Management to reduce fire frequency and intensity in savannas could substantially increase the amount of carbon stored in woody biomass. We addressed two questions: (1) are northern Australian savannas thickening; and (2) to what extent, and by what demographic processes, does fire affect woody biomass accumulation? Location Three large national parks, covering 24,000 km 2 , in monsoonal northern Australia. Methods We examined changes in woody biomass carbon stocks – inferred from tree basal area and the density of woody understorey plants – over a 10year period in 136 savanna monitoring plots. We statistically assessed these changes in relation to fire frequency and severity. We used a meta-analysis to identify general trends in woody cover in Australian savannas over the last half-century. Results Woody biomass carbon stocks were relatively stable across the three national parks, but rates of change were statistically indistinguishable from earlier findings of a weak thickening trend. Change was negatively correlated with fire frequency, particularly the frequency of severe fires. High frequencies of severe fires decreased rates of accumulation of biomass by existing trees (through reductions in tree growth and death of individual stems), rather than whole-tree mortality and suppression of recruitment. However, across northern Australia, our meta-analysis identified a general, albeit weak, trend of woody thickening. Main conclusions The drivers of northern Australia’s weak thickening trend are uncertain, but likely candidates include increasing atmospheric CO2 concentration and water availability, and pastoral intensification. We demonstrate that changes to fire management have the potential to either increase or decrease rates of woody thickening relative to any underlying trend. Understanding how savanna fires affect woody biomass, and how fire effects are mediated by climate and CO2, are essential research priorities to predict the fate of savannas.
4 citations
TL;DR: In this article, the authors investigated the effect of fire suppression in western US forests on carbon sink rates and concluded that fire-suppression, independent of logging, has brought about a decrease in live, aboveground tree carbon via increased mortality of large trees in western United States forests over a 60 year span.
Abstract: [1] Fellows and Goulden [2008, hereafter F-G] have recently claimed that fire-suppression, independent of logging, has brought about a decrease in live, aboveground tree carbon via increased mortality of large trees in western US forests over a 60 year span However the study, restricted for unspecified reasons to part of California, has several problems that I believe collectively invalidate their principal conclusion I detail these here in increasing order of perceived importance [2] Beginning with the interpretation of the literature, the suppression-induced carbon sink rates of 23 Mg/ha/yr contested by F-G [from Houghton et al, 1999], apply only to the highly fire-prone western ponderosa pine woodlands, as stated by Houghton et al [1999, Table 2] Houghton et al [1999] were also clear that their estimate was [Houghton et al, 1999, p 575] ‘‘an upper limit for the sink strength of US ecosystems’’ Ponderosa pine forests occur generally at low tomid elevations, but F-G analyzed data only fromCalifornia wilderness areas, which on the whole occupy the higher elevations and contain large areas of other forest types, such as true fir forests and subalpine woodlands [Barbour and Minnich, 2000] A significant fraction of their plots were from above 1830 m (6000 ft), or even 2438 m (8000 ft), beyond the primary range of ponderosa pine forests in California The effects of fire suppression in western US forests are well known to vary strongly with environment and forest type [eg, Agee, 1993] [3] Both the 1930s (Vegetation Type Mapping Project (VTM)) and 1990s (Forest Inventory Analysis (FIA)) data reportedly used by F-G are potentially problematic, based on specific knowledge of their purposes and methods, and the claims made by F-G [Bouldin, 1999; Keeley, 2004; Waddell and Hiserote, 2005] (see also United States Forest Service, Forest Inventory and Analysis National Program, data and tools,http://fiafsfedus/tools-data/defaultasp,2009,PNW-FIA data, http://wwwfsfedus/pnw/fia/publications/data/index shtml#1a, 2009, andPacificSouthwestRegion,RemoteSensing LaboratoryVegetation Inventory Data, http://wwwfsfedus/ r5/rsl/projects/inventory/designsshtml, 2009 and VTM, http:// vtmberkeleyedu/, 2009) Regarding the FIA data, F-G indicate in their Table 1 that they use 140 wilderness FIA plots sampled between 1990 and 1994 in northern California and/or the Sierra Nevada The only FIA plots installed in wilderness areas in that region and at that time were in the Sierra Nevada and far northwestern California Since almost no VTM plots were collected in the latter for the necessary comparisons, this implies that all 140 FIA plots must have been located in eastern northern California (ENC: SierraNevada, Cascades and Modoc Plateau), but this exceeds the number ( 106) actually collected there Of these, 87 (83%) were located on the Inyo National Forest, an area dominated by cold and/or dry alpine/subalpine or woodland ecosystems above 2438 m (8000 ft) elevation Conversely, most VTM plots in ENC were established on the much more productive west side of the Sierra Nevada (VTM, http://vtmberkeley edu/, 2009) It would not be at all surprising to find an apparent decrease in carbon if this was in fact the comparison made If, on the other hand, the authors only used that minority of VTM plots from the colder Inyo NF high elevations, one could well question how this represents the effect of fire reduction on carbon accrual in California forests as a whole, much less the entire western United States [4] There is also a definitional issue relating to the plot selection criterion The authors implicitly defined forested areas as those having a minimum of 1 tree per plot ( 12 trees/ha for the 008 ha VTM plots) Given that much of the California landscape was responding to fire reduction policies over the 20th century [Skinner and Chang, 1996], including upper montane forests where the evidence of catastrophic fires in the 19th century is strong [eg, Leiberg, 1902, pp 37, 41, 106, and 117], the area meeting this criterion may well have increased over time This would affect both the area of the landscape sampled, and the demographic character of the plots included in the sample, changes which must be accounted for in regionwide estimates of forest carbon dynamics [5] Relevant empirical studies bearing on the topic are scarce, as it is not trivial to separate out fire suppression effects from confounding factors such as logging, climate change and other human impacts However, the available studies do not support F-G’s conclusion Although climate change [eg, Pierce et al, 2008] is indeed likely causing increased tree mortality in old growth forests in the western United States in recent decades [van Mantgem et al, 2009] this does not mean that fire reduction over the last 100 to 150 years has not had a much greater, opposing carbon impact For example, Leiberg [1902], in a thorough early survey, noting the strong effect of fire on tree demography throughout the northern Sierra Nevada, stated [Leiberg, 1902, p 85] ‘‘ this region does not contain more than 35 percent of the timber it is capable of carrying, and the deficiency is wholly due to forest fires ’’, and Gruell [2001] has provided long-term photographic evidence of both forest expansion and increased density and canopy cover in many locations in the Sierra since the 19th century GEOPHYSICAL RESEARCH LETTERS, VOL 36, L21403, doi:101029/2009GL039391, 2009 Click Here for Full Article
4 citations
References
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Book•
06 Mar 1997
TL;DR: In this paper, the authors present a perspective of the global cycle of nitrogen and phosphorous, the global water cycle, and the global sulfur cycle from a global point of view.
Abstract: Part 1 Processes and reactions: origins the atmosphere the lithosphere the terrestrial biosphere biogeochemical cycling on land biogeochemistry in freshwater wetlands and lakes rivers and estuaries the sea. Part 2 Global cycles: the global water cycle the global carbon cycle the global cycle of nitrogen and phosphorous the global sulfur cycle a perspective.
3,871 citations
TL;DR: Slowing deforestation, combined with an increase in forestation and other management measures to improve forest ecosystem productivity, could conserve or sequester significant quantities of carbon.
Abstract: Forest systems cover more than 4.1 x 109 hectares of the Earth9s land area. Globally, forest vegetation and soils contain about 1146 petagrams of carbon, with approximately 37 percent of this carbon in low-latitude forests, 14 percent in mid-latitudes, and 49 percent at high latitudes. Over two-thirds of the carbon in forest ecosystems is contained in soils and associated peat deposits. In 1990, deforestation in the low latitudes emitted 1.6 ± 0.4 petagrams of carbon per year, whereas forest area expansion and growth in mid- and high-latitude forest sequestered 0.7 ± 0.2 petagrams of carbon per year, for a net flux to the atmosphere of 0.9 ± 0.4 petagrams of carbon per year. Slowing deforestation, combined with an increase in forestation and other management measures to improve forest ecosystem productivity, could conserve or sequester significant quantities of carbon. Future forest carbon cycling trends attributable to losses and regrowth associated with global climate and land-use change are uncertain. Model projections and some results suggest that forests could be carbon sinks or sources in the future.
3,175 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...…biomass creates ;20–25% of annual anthropogenic CO2 (Andreae 1991, Schimel 1995), modifications of fire frequency may significantly change regional and global C budgets (e.g., Fahenstock and Agee 1983, Andreae 1991, Stocks 1991, Dixon and Krankina 1993, Dixon et al. 1994, Sohngen and Haynes 1997)....
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...This work was supported by National Science Foundation Grant 9411972 and by the Andrew Mellon Foundation....
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...Our work supports the proposal that increased fire suppression and decreased anthropogenic burning of vegetation could significantly influence global carbon dynamics (Dixon et al. 1994, Sampson and Clark 1995, Sohngen and Haynes 1997, San Jose et al. 1998)....
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...Dixon et al. (1994) calculated that fire management in Russia could lead to long-term C storage of 0.6 3 1015 g C/yr....
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TL;DR: The terrestrial biosphere plays an important role in the global carbon cycle as mentioned in this paper, which is the fluxes of carbon among four main reservoirs: fossil carbon, the atmosphere, the oceans, and the terrestrial Biosphere.
Abstract: The terrestrial biosphere plays an important role in the global carbon cycle. In the 1994 Intergovernmental Panel Assessment on Climate Change (IPCC), an effort was made to improve the quantification of terrestrial exchanges and potential feedbacks from climate, changing CO2, and other factors; this paper presents the key results from that assessment, together with expanded discussion. The carbon cycle is the fluxes of carbon among four main reservoirs: fossil carbon, the atmosphere, the oceans, and the terrestrial biosphere. Emissions of fossil carbon during the 1980s averaged 5.5 Gt y−1. During the same period, the atmosphere gained 3.2 Gt C y−1 and the oceans are believed to have absorbed 2.0 Gt C y−1. The regrowing forests of the Northern Hemisphere may have absorbed 0.5 Gt C y−1 during this period. Meanwhile, tropical deforestation is thought to have released an average 1.6 Gt C y−1 over the 1980s. While the fluxes among the four pools should balance, the average 198Ds values lead to a ‘missing sink’ of 1.4 Gt C y−1 Several processes, including forest regrowth, CO2 fertilization of plant growth (c. 1.0 Gt C y−1), N deposition (c. 0.6 Gt C y−1), and their interactions, may account for the budget imbalance. However, it remains difficult to quantify the influences of these separate but interactive processes. Uncertainties in the individual numbers are large, and are themselves poorly quantified. This paper presents detail beyond the IPCC assessment on procedures used to approximate the flux uncertainties.
Lack of knowledge about positive and negative feedbacks from the biosphere is a major limiting factor to credible simulations of future atmospheric CO2 concentrations. Analyses of the atmospheric gradients of CO2 and 13 CO2 concentrations provide increasingly strong evidence for terrestrial sinks, potentially distributed between Northern Hemisphere and tropical regions, but conclusive detection in direct biomass and soil measurements remains elusive.
Current regional-to-global terrestrial ecosystem models with coupled carbon and nitrogen cycles represent the effects of CO2 fertilization differently, but all suggest longterm responses to CO2 that are substantially smaller than potential leaf- or laboratory whole plant-level responses. Analyses of emissions and biogeochemical fluxes consistent with eventual stabilization of atmospheric CO2 concentrations are sensitive to the way in which biospheric feedbacks are modeled by c. 15%. Decisions about land use can have effects of 100s of Gt C over the next few centuries, with similarly significant effects on the atmosphere.
Critical areas for future research are continued measurements and analyses of atmospheric data (CO2 and 13CO2) to serve as large-scale constraints, process studies of the scaling from the photosynthetic response to CO2 to whole-ecosystem carbon storage, and rigorous quantification of the effects of changing land use on carbon storage.
1,510 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...2680 Key words: carbon storage; fire suppression; missing carbon; oak savanna....
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...San Jose et al. (1998) calculated that fire suppression, by causing the transformation of the 2.8 3 107 ha Venezuelan Orinoco Llanos from grassland to semideciduous forest, could lead to a C sink of 0.08 3 1015 g C/yr....
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...Atmospheric CO2 is currently accumulating at ;3.2 3 1015 g C/yr (Schimel 1995)....
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...Dixon et al. (1994) calculated that fire management in Russia could lead to long-term C storage of 0.6 3 1015 g C/yr....
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...Because the burning of ecosystem biomass creates ;20–25% of annual anthropogenic CO2 (Andreae 1991, Schimel 1995), modifications of fire frequency may significantly change regional and global C budgets (e.g., Fahenstock and Agee 1983, Andreae 1991, Stocks 1991, Dixon and Krankina 1993, Dixon et al.…...
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TL;DR: The first edition of Schlesinger's Biogeochemistry in 1991 was an early entry in the field of Earth system science/global change, and has since gained sufficient popularity and demand to merit a second, extensively revised edition.
Abstract: Compared to the well-established disciplines, the field of Earth system science/global change has relatively few books from which to choose. Of the small subset of books dealing specifically with biogeochemical aspects of global change, the first edition of Schlesinger's Biogeochemistry in 1991 was an early entry. It has since gained sufficient popularity and demand to merit a second, extensively revised edition.
The first part of the book provides a general introduction to biogeochemistry and cycles, and to the origin of elements, our planet, and life on Earth. It then describes the functioning and biogeochemistry of the atmosphere, lithosphere, biosphere, and hydrosphere, including marine and freshwater systems. Although system function and features are stressed, the author begins to introduce global change topics, such as soil organic matter and global change in Chapter 5, and landscape and mass balance in Chapter 6.
1,075 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...This work was supported by National Science Foundation Grant 9411972 and by the Andrew Mellon Foundation....
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...Moreover, the immense global extent of tropical savanna and woodland, 2.45 3 109 ha (Schlesinger 1997), suggests that even moderate fire suppression in this ecosystem type could provide a globally significant C sink....
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TL;DR: The rates at which lands in the United States were cleared for agriculture, abandoned, harvested for wood, and burned were reconstructed from historical data for the period 1700-1990 and used in a terrestrial carbon model to calculate annual changes in the amount of carbon stored in terrestrial ecosystems, including wood products.
Abstract: The rates at which lands in the United States were cleared for agriculture, abandoned, harvested for wood, and burned were reconstructed from historical data for the period 1700-1990 and used in a terrestrial carbon model to calculate annual changes in the amount of carbon stored in terrestrial ecosystems, including wood products. Changes in land use released 27 +/- 6 petagrams of carbon to the atmosphere before 1945 and accumulated 2 +/- 2 petagrams of carbon after 1945, largely as a result of fire suppression and forest growth on abandoned farmlands. During the 1980s, the net flux of carbon attributable to land management offset 10 to 30 percent of U.S. fossil fuel emissions.
1,035 citations
"Fire suppression and ecosystem carb..." refers background or methods in this paper
...Houghton et al. (1999) estimated various sources of C storage in the United States....
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...Because fire suppression might lead to a period of C accumulation (Houghton et al. 1999), current fire suppression in the United States (Fig....
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...This work was supported by National Science Foundation Grant 9411972 and by the Andrew Mellon Foundation....
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...2680 Key words: carbon storage; fire suppression; missing carbon; oak savanna....
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